Linear time-history analysis of buildings using transfer functions derived from ambient vibrations.

Abstract

Finite element models (FEMs) are widely used to evaluate the seismic response of structures; however, their accuracy is affected by uncertainties in material properties, geometry, soil conditions, and soil–structure interaction, and their development and calibration are often time-consuming. This study proposes a rapid alternative for existing buildings based solely on ambient vibration measurements. The method determines the building transfer function from synchronized ground and roof recordings and uses it to predict the structural response to dynamic excitation through frequency-domain analysis. The methodology was applied to an instrumented confined-masonry and reinforced-concrete building. Transfer functions obtained from ambient vibrations were used to predict the response to three recorded earthquakes and were compared with both a calibrated finite element model and measured data. The proposed transfer-function ambient-vibration (TF-AV) model showed good agreement with the measurements, with Pearson correlation coefficients ranging from 0.847 to 0.987 and errors in peak displacement below 10% for all cases. Its performance was comparable to that of the calibrated FEM while requiring substantially less computational effort. These results indicate that transfer functions derived from ambient vibrations can provide a practical and efficient tool for rapid linear seismic-response assessment of existing buildings.